In 1663 John Manners 1st Duke Rutland (age 24) and Anne Pierrepont (age 32) were separated. He obtained a "separation from bed and board" on the grounds of her adultery. See Lord Ross Divorce. Around this time it appears her father Henry Pierrepont 1st Marquess Dorchester (age 56) offered John Manners 1st Duke Rutland (age 24) a duel which he declined. See Lord Ross Divorce.

In 1667 John Manners 1st Duke Rutland (age 28) procured an Act of Parliament by which his issue since 1659 were legally illegitimate barring them from inheriting his title. See Lord Ross Divorce.

In 1670 John Manners 1st Duke Rutland (age 31) procured permission from Parliament to re-marry so that his title would continue. See Lord Ross Divorce.

Evelyn's Diary. 22 Mar 1670. I went to Westminster, where in the House of Lords I saw his Majesty (age 39) sit on his throne, but without his robes, all the peers sitting with their hats on; the business of the day being the divorce of my Lord Ross. Such an occasion and sight had not been seen in England since the time of Henry VIII.

The Lord Ross Divorce attracted considerable public attention since it highlighted the shortcomings of the divorce laws. Anne Pierrepont had clearly committed adultery since she was in London at the time of the conception whilst her husband, known by the courtesy title Lord Ross was at Belvoir Castle [Map]. The child would be considered legitimate since the parents were married; the law made no provision for adultery or divorce. He was forced to seek legislation in Parliament that made the child illegitimate and, therefore, unable to inherit his title. He was further compelled to seek legislation so that he could marry again so that he could produce an heir.

King Charles II of England Scotland and Ireland took a more than passing interest, it is believed, since divorce may have been an option since he and his wife Catherine of Braganza Queen Consort England had not had any children in their eight years of marriage despite he having had eight illegitimate children.